Fluid delivery set

ABSTRACT

A fluid delivery set has three lengths of flexible tubing. The first length of flexible tubing at one end is connectable to or integral with a supply container for enteral or parenteral fluid, and at the other end is connected to the inlet of a drip chamber. The second length of flexible tubing is connected at one end to the outlet of the drip chamber, and at the other end to the inlet of a retention/connector device that has about a 90° bend therein. The third length of flexible tubing is connected at one end to outlet of the retention/connector device, and at the other end is connectable to or integral with a means for introducing an enteral or parenteral fluid into the body of a patient. Preferably, a tension responsive pinch valve is operatively associated with the second length of flexible tubing.

FIELD OF THE INVENTION

The present invention relates to a fluid delivery set, commonly referredto as an administration set or a feeding set, for introducing an enteralfluid or a parenteral fluid into the body of a patient.

BACKGROUND OF THE INVENTION

The present invention is a fluid delivery set that may be employed inconjunction with a rotary peristaltic pump on nearly any occasionwherein enteral or parenteral fluids are to be delivered to a patientthrough a flexible tubing. Parenteral fluids are delivered into thecirculatory system of a patient. Enteral fluids are delivered into thegastrointestinal tract of the patient.

Rotary peristaltic pumps are well known and are described in a number ofU.S. Pat. Nos. , such as, 5,250,027; 5,057,081; 4,913,703; 4,884,013;4,832,584; 4,722,734; 4,720,636; 4,708,604; 4,690,673; 4,688,595;4,545,783; and 4,513,796. Rotary peristaltic pumps commonly include amotor driven peristaltic rotor mounted on a shaft extending out throughthe front wall of the pump housing. The peristaltic rotor carries anarray of two or more circumferentially, i.e., angularly, spaced apartrollers. The peristaltic rotor is designed to have a portion of theflexible tubing of the feeding set wrapped part way around the rollerarray under tension thereagainst or confined between the rollers and anopposing arcuate surface. As the motor within the pump housing rotatesthe shaft on which the peristaltic rotor is mounted, the spaced apartrollers are sequentially brought into contact with the flexible tubingwith each revolution of the motor shaft and each roller in turncompresses a portion of the tubing to form an occlusion. The occlusionis advanced along the tubing as the peristaltic rotor turns and theroller advances along the tubing, the occlusion disappearing where thetubing diverges tangentially from the rotor. A predetermined amount offluid is contained between successive occlusions so that a predeterminedvolume of fluid is advanced in a peristaltic manner through the tubingwith each revolution of the rotor. Accordingly, the amount of fluid tobe delivered to the patient may be regulated by controlling the rate ofrotation of the peristaltic rotor and the time duration of the fluiddelivery procedure.

Fluid delivery sets, also referred to herein as feeding sets, typicallycomprise a drip chamber having the outlet end connected to anelastically flexible tubing, such as a silicone rubber tube, orinterconnected lengths thereof, that in turn connect, directly orthrough an adapter, to the requisite device, such as a needle or tube,for parenteral or enteral administration of fluid to the patient. Theinlet of the drip chamber is adapted to receive, directly or through aconnecting piece of flexible tubing, enteral or parenteral fluid from asupply container thereof, usually a hanging container. A portion of theflexible tubing is appropriately associated with a pump if the same isto be employed. For example, if the pump is a rotary peristaltic pump,the flexible tubing is usually wrapped partially, i.e., less than onecomplete turn, around the rotor as described above.

The fluid delivery set is typically changed every day. It is importantthat the fluid delivery set is manufactured according to fairly rigidmanufacturing specifications so that delivery volumes are accuratelypredetermined and controlled and consistently produced from set to set.The portion of the flexible tubing, which together with the drip chambermakes up the fluid delivery set, i.e., feeding set, for mounting on thepump, for example, should be cut to a consistent length for each set andhave a lumen of constant and consistent internal diameter and aconsistent flexibility and elasticity as determined by urometer tests sothat the internal diameter of the lumen will be consistent for eachfluid delivery set when placed in tension around the rotor of theperistaltic pump. The drip chamber dimensions should also be consistent,especially in length, so that the drip chamber may be properly alignedwith an adjacent drop sensor on the pump housing, if such a sensor isused.

The portion of each fluid delivery set that is typically assembled witha rotary peristaltic pump housing is placed into an operative positionby inserting the drip chamber into a complementary retention recess orpocket formed in the housing, tangentially upward from a circumferentialedge of the rotor. The flexible tubing which extends from the bottom ofthe drip chamber is stretched sufficiently around the roller array ofthe peristaltic rotor to provide for the peristaltic action of therollers and back up along another channel or groove formed in the pumphousing and leading tangentially upwardly from a circumferential edge ofthe rotor to supporting means such as a retention recess or pocketformed in the pump housing. Usually the flexible tubing will have formedthereon, or attached there around, a collar or flange that engages withan upper surface of the portion of the pump housing which defines theretention recess or pocket. The collar or flange is located along theflexible tubing at a linear position that will necessitate the flexibletubing being in tension in order to place the collar in the retentionrecess. In most known devices of the type generally described above, theflexible tubing more usually is positioned to extend out above the pumphousing in a nearly vertical direction and arch over and away from thepump housing towards the patient being fed or treated, or, the flexibletubing is positioned in an arcuate groove formed in the pump housingleading upwardly as well as laterally away from the retention recess tothe edge of the housing, from which point the flexible tubing arches onover and away from the pump housing towards the patient. The arcuategroove is of great enough radius, such as an inch, to not wrinkle orcrimp the flexible tubing and reduce the cross-section of the lumen ofthe flexible tubing so as to significantly limit flow of liquidtherethrough. Examples of the arrangement with the path of delivery ofthe fluid extending up above the pump housing are shown in U.S. Pat.Nos. 5,380,173; 5,250,027; 5,147,312; 5,133,650; 5,057,081; 4,913,703;4,836,752; 4,832,584; 4,688,595; 4,552,516; 4,515,535; 4,513,796; and4,231,725. An example of the arrangement with the delivery of the fluidthrough the tubing extending up from the peristaltic rotor and outlaterally along an arcuate groove in the housing is shown in U.S. Pat.No. 4,884,013.

In still other arrangements the flexible tubing receiving fluid from theoutlet of the drip chamber describes about a 180 degree arcuate bendmating the curvature of the peristaltic rotor and extends horizontallyto and from the rotor about which it is to a large degree wrapped andheld under tension by retaining means on the pump housing or by rotorcompression as illustrated in U.S. Pat. Nos. 5,082,429; 4,886,431;4,813,855; 4,722,734 and 4,545,783. In yet another arrangement theflexible tubing leading from the drip chamber or other supply means isbrought upwardly from below the peristaltic rotor of the peristalticpump and over the rotor and back downwardly to then extend laterallytowards the patient. This configuration is illustrated in U.S. Pat. Nos.5,266,013; 5,110,270; 4,720,636; 4,708,604; 4,256,442; and 3,963,023.

With some of these designs or configurations it is possible for movementof a pole supporting a hanging container or other supply support, orindeed, movement of the supply container, per se, to cause the flexibletubing to become loosened or disengaged from the peristaltic rotor, or arestless patient may tug on and accidentally displace the flexibletubing from the retention recess or pocket on the downstream side of theperistaltic rotor, resulting in disengagement of the tubing fromcompression by the peristaltic rotor. In these situations, it ispossible to have an uncontrolled rate of gravity-induced flow of theenteral or parenteral fluid to the patient because the rollers of therotor are not properly compressing, i.e., occluding, the flexible tubingto restrict the flow of fluid through the feeding set to a pre-selectedrate.

SUMMARY OF THE INVENTION

There is provided in accordance with one aspect of the present inventiona fluid delivery set comprising: a fluid communication means having afirst end which is connectable to or integral with a supply container ofan and a second end which is connectable to or integral with a means forintroducing an enteral or parenteral fluid into the body of a patient;the fluid communication means comprising a drip chamber with a retentionelement associated therewith and a retention/connector device, and, atleast first, second and third lengths of flexible tubing, the firstlength of flexible tubing being connected to the drip chamber and beingconnectable to or integral with a supply container, the second length offlexible tubing connecting the drip chamber and the retention/connectordevice, and the third length of flexible tubing being connected to theretention/connector device and being connectable to or integral with adevice for administering the fluid within the body of a patient; and thefluid communication means at about the retention/connector device beingshaped into a bend with a radius of no more than 0.5 inch and at anangle in the range of about 78 to about 102 degrees.

There is provided in accordance with a second aspect of the invention afluid delivery set for enteral or parenteral fluids comprising: a dripchamber having an inlet and an outlet, a retention/connector device, andat least first, second and third lengths of flexible tubing each havingfirst and second ends; the inlet of the drip chamber being connected tothe first end of the first length of flexible tubing and the second endof the first length of flexible tubing being connectable to or integralwith a supply container; the outlet of the drip chamber being connectedto the first end of the second length of flexible tubing, the second endof the second length of flexible tubing being connected to theretention/connector device, a first end of the third length of flexibletubing being connected to the retention/connector device, and a secondend of the third length of flexible tubing being connectable to orintegral with a device for administering a fluid within the body of apatient; the drip chamber having a first retention element associatedwith the upper part thereof, the first retention element being adaptedto fit into a first retentive and supportive receptacle of the housingof a rotary peristaltic pump therefor; the retention/connector devicebeing hollow tubular in form having a fluid passageway formedtherethrough and formed of the juncture of two tubular leg portions towhich the second and third lengths of flexible tubing are connected,respectively, the retention/connector device being adapted to fit into asecond retentive receptacle of the housing of a rotary peristaltic pump;the leg portions of the retention/connector device being joined at abouta right angle bend wherein the cross section of the lumen of theretention/connector device is not substantially reduced when the bendradius is not greater than about 0.5 inch.

Preferably the fluid delivery set is also provided with a tensionresponsive pinch valve associated with a portion of the flexible tubing,the pinch valve pinching the flexible tubing sufficiently tosubstantially prevent fluid flow therethrough when this portion of theflexible tubing is not under operative tension.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view in front elevation of a peristaltic pump and fluiddelivery set assembly according to the invention connected at the inletend of the fluid delivery set to a supply container of liquid enteralnutritional product, here suspended from a support on a pole, and,connected at the discharge end of the fluid delivery set to a feedingtube extending into the stomach of a patient whose abdomen is shown infragmentary view, partly broken away and in section;

FIG. 2 is a perspective view of a peristaltic pump and fluid deliveryset assembly according to the invention;

FIG. 3 is a perspective view of the peristaltic pump of FIG. 2, withoutthe complementary fluid delivery set assembled therewith;

FIG. 3A is a greatly enlarged view of the encircled portion of FIG. 3;

FIG. 4 is a view in front elevation of the peristaltic pump and fluiddelivery set assembly of FIG. 2;

FIG. 4A is a fragmentary view in section taken along the line 4A--4A ofFIG. 4;

FIG. 5 is a side view of the peristaltic pump and fluid delivery setassembly of FIG. 4;

FIG. 6 is a top view of the peristaltic pump and fluid delivery setassembly of FIG. 4, while within the encircled portion the cap-like orcollar-like first retention element is partly broken away for purposesof illustration of the relationship of the retention element and one ofthe bosses on the floor of the first retentive recess;

FIG. 6A is an enlarged view of the encircled portion of FIG. 6 with theretention element shown only in dotted outline for purposes ofillustration so that the nature of the floor of the first retentiverecess and the connecting downwardly extending guideway will be betterunderstood;

FIG. 7 is an enlarged fragmentary view in vertical section of theperistaltic pump and fluid delivery set assembly of FIG. 4 taken alongthe line 7--7 of FIG. 4;

FIG. 8 is a fragmentary view in horizontal section of the peristalticpump and fluid delivery set assembly of FIG. 4 taken along the line 8--8of FIG. 4;

FIG. 8A is a further enlarged fragmentary view in vertical section ofthe peristaltic pump and fluid delivery set assembly of FIG. 4 takenalong the line 8A--8A of FIG. 8;

FIG. 9 is a perspective view of a fluid delivery set according to theinvention with the first and third flexible tubing portions truncatedand foreshortened;

FIG. 10 is a front view of the fluid delivery set of FIG. 9;

FIG. 10A is a view in section taken along the line 10A--10A of FIG. 10;

FIG. 11 is a perspective view of a length of the flexible tubing of afluid delivery set of the invention, such as the second length 49, witha novel pinch valve element telescoped thereon kinking the tubing invalving action when the tubing is not under tension;

FIG. 12 is an enlarged perspective view of the pinch valve element ofFIG. 11 before being telescopically mounted on the flexible tubing toprovide valving action;

FIG. 13 is a side elevation view of the components of a pinch valve;

FIG. 14 is a side view of a section of flexible tubing that has beenkinked by the novel pinch valve element of FIG. 12;

FIG. 15 is a perspective view of a fluid delivery set like that shown inFIG. 9 but having a pinch valve element telescoped on the flexibletubing near the second retention element;

FIG. 16 is a front view of the fluid delivery set of FIG. 15;

FIG. 17 is a view, partly in front elevation and partly fragmentary andin section, of the peristaltic pump-fluid delivery set assembly of theinvention connectable at the inlet end to the screw cap opening of ahanging supply container of a liquid enteral nutritional product, and atthe outlet end being connected to a nasogastric feeding tube extendinginto the stomach of a patient;

FIG. 18 is a view, partly in front elevation and partly fragmentary andin section, of the peristaltic pump-fluid delivery set assembly of theinvention connectable at the inlet end to the pierceable cap of ahanging supply container of a liquid enteral nutritional product, and atthe outlet end being connected to a feeding tube leading into thejejunum of a patient;

FIG. 19 is a view, partly in front elevation and partly fragmentary andin section, similar to FIG. 18 but with the outlet end of the fluiddelivery set connected to a feeding tube extending through a stoma inthe abdominal wall and into the stomach of the patient;

FIG. 20 is a view, partly in front elevation and partly fragmentary, ofa peristaltic pump-fluid delivery set assembly of the invention with theinlet end of the first length of flexible tubing connected to a hangingsupply container of a parenteral fluid and the outlet of the thirdlength of flexible tubing connected to a needle extending into a vein inthe arm of a patient;

FIG. 21 is a perspective view of a peristaltic pump according to theprior art;

FIG. 22 is a partly fragmentary perspective view of a hanging supplycontainer of an enteral or parenteral fluid shown connected to the inletend of a fluid delivery set-peristaltic pump assembly according to theprior art, the fluid delivery set assembled with the prior artperistaltic pump of FIG. 21;

FIG. 23 is a perspective view of a preferred form of right angleretention/connector element suitable for connecting the second and thirdlengths of the flexible tubing of the fluid delivery set of theinvention;

FIG. 24 is a top view of the retention/connector element of FIG. 23;

FIG. 25 is a view in vertical section of the retention/connector elementof FIG. 23 taken along the line 25--25 of FIG. 24;

FIG. 26 is a side view of the retention/connector element of FIG. 23;

FIG. 27 is a front view of the retention/connector element of FIG. 23;

FIG. 28 is a bottom view of the retention/connector element of FIG. 23looking in the direction indicated by the arrow 28 in FIG. 27;

FIGS. 29 to 34 show alternative embodiments of right angleretention/connector elements with various forms of tabs for grasping,except for the retention-connector element of FIG. 29 which has only aretention tab;

FIGS. 35 to 38 are perspective views of more alternative embodiments ofretention/connector elements with various shaped retention tabs and nothaving a right angle formed in the channel within theretention/connector element;

FIG. 39 is a perspective view of yet another alternative embodiment ofthe retention/connector element which provides a right angled passagewaytherethrough but supports the third length of flexible tubing forwardlyof the pump housing;

FIG. 40 is a fragmentary view mostly in vertical section taken throughthe front wall of the pump housing adjacent the pump rotor showing theretention/connector element of FIG. 39 assembled with a peristaltic pumpof the invention;

FIG. 41 is a fragmentary portion of FIG. 40 further enlarged to moreclearly show the flanges of the recess as well as of theretention/connector element;

FIGS. 42 and 43 are perspective views similar to FIGS. 11 and 12,respectively, of an alternative pinch valve element assembled with alength of flexible tubing and of the pinch valve element by itself;

FIGS. 44 and 45 are perspective views similar to FIGS. 11 and 12,respectively, of an alternative pinch valve element assembled with alength of flexible tubing and of the pinch valve element by itself;

FIGS. 46 and 47 are perspective views similar to FIGS. 11 and 12,respectively, of an alternative pinch valve element assembled with alength of flexible tubing and of the pinch valve element by itself;

FIG. 47A is a rear view of the pinch valve element of FIG. 47;

FIGS. 48 and 49 are perspective views similar to FIGS. 11 and 12,respectively, of an alternative pinch valve element assembled with alength of flexible tubing and of the pinch valve element by itself;

FIG. 50 is a perspective view of a length of flexible tubing partlyassembled with an alternative pinch valve element;

FIG. 51 is a perspective view of the pinch valve of FIG. 50 fullyassembled, the flexible tubing not being under tension;

FIG. 52 is a perspective view of the flexible tubing and pinch valve ofFIG. 51 with the tubing under sufficient tension to open the pinchvalve;

FIG. 53 is a view in front elevation of yet another alternative pinchvalve element;

FIG. 54 is a view in side elevation of an assembly of the pinch valveelement of FIG. 53 and a length of flexible tubing, the tubing being ina relaxed state;

FIG. 55 is a view in side elevation of the assembly of FIG. 54 with theflexible tubing under sufficient tension to open the pinch valve;

FIGS. 56 and 57 are longitudinal and transverse cross-sectional views,respectively, of another form of tension responsive pinch valve in whicha bent spring wire is embedded in the wall of a section of flexibletubing;

FIG. 57A is a transverse cross-sectional view of another form of tensionresponsive pinch valve similar in mode of action to that of the pinchvalve of FIGS. 56 and 57, but in which the bent spring wire is bonded oradhesively attached longitudinally to the exterior of the wall of asection of flexible tubing;

FIG. 58 is a fragmentary side view of an assembly of yet another form ofpinch valve element with a length of flexible tubing which assembly is atension-responsive valve;

FIG. 59 is a perspective view of the front and side of an assemblyapparatus which has been used to assemble a pinch valve element with alength of tubing;

FIG. 60 is a perspective view of the back and side of the assemblyapparatus of FIG. 59;

FIG. 61 is a front elevation view of the assembly apparatus of FIG. 59;

FIG. 62 is very greatly enlarged fragmentary view of the portion of FIG.61 encircled by a dashed line;

FIG. 63 is a view in vertical section of the assembly apparatus takenalong the line 63--63 of FIG. 61;

FIG. 64 is an exploded perspective view of the components of theassembly apparatus with a corner of the base plate cut away for purposesof illustration;

FIG. 65 is a greatly enlarged perspective view of an ejector block whichmay be used as a part of a sub-assembly identified by referencecharacter 330 in FIG. 64;

FIG. 66 is a greatly enlarged perspective view of another ejector blockwhich may be used in a modification of the sub-assembly identified byreference character 330 in FIG. 64;

FIG. 67 is an enlarged exploded perspective view of some of thecomponents of the subassembly identified by reference character 330 inFIG. 64, including the ejector block of FIG. 65;

FIG. 68 is an enlarged exploded perspective view of all the componentsof the subassembly identified by reference character 330 in FIG. 64 withthe components shown in FIG. 67 already assembled together;

FIG. 69 is a greatly enlarged perspective view of an "L"-shaped spreaderfinger element showing the guide pin extending laterally from the legportion;

FIG. 70 is a very greatly enlarged partly exploded perspective view ofthe sub-assembly identified by reference character 330 in FIG. 64 in theprocess of being assembled;

FIG. 71 is a very greatly enlarged perspective view of the sub-assemblyidentified by reference character 330 in FIG. 64;

FIG. 72 is a perspective view of the reverse or inside face of the coverplate;

FIG. 73 is a perspective view of the assembly apparatus with thecomponents of a pinch valve shown in exploded view relationship about tobe assembled using the assembly apparatus;

FIG. 74 is a fragmentary perspective view of the assembly apparatusshown with a first tubular segment end portion of the pinch valveelement oriented for placing over, i.e., around, the fingers of thespreader finger elements;

FIG. 75 is a view similar to FIG. 74 with the first tubular segment endportion of the pinch valve element slid onto the cluster of spreaderfingers to commence the assembly process;

FIG. 76 is a view in vertical section of the assembly apparatus likethat shown in FIG. 63, but with a first tubular segment, namely atubular end portion of the pinch valve element, emplaced over thespreader fingers as in FIG. 75;

FIG. 77 is a perspective fragmentary view similar to FIG. 75 showing thefirst tubular segment end portion of the pinch valve element shown inFIG. 75 stretched open radially to receive therethrough the length oftubing upon which the pinch valve element is to be telescopicallyassembled;

FIG. 78 is a fragmentary view in section of the assembly apparatus andstretched first tubular segment end portion of the pinch valve elementshown in FIG. 77, and with the length of tubing inserted into theapparatus over the central guide rod and through the cluster of spreaderfingers;

FIG. 79 is a front elevation of the portion of the assembly apparatusencompassed by the cover plate at the point of the assembly processillustrated in FIGS. 77 and 78;

FIG. 80 is a fragmentary view in section of the assembly apparatus withthe tubular segment end portion of the pinch valve relaxed upon thelength of tubing and with the ejector piston moved forward;

FIG. 81 is a front elevation of the portion of the assembly apparatusencompassed by the cover plate at the point of the assembly processillustrated in FIG. 80;

FIG. 82 is a fragmentary perspective view of assembly apparatus closelysimilar to that of FIG. 74 but adapted with a longer ejector block forthe next stage of assembling a pinch valve assembly with the secondtubular end portion of the pinch valve element oriented for placingover, i.e., around, the spreader fingers and with the leading end of thelength of tubing bent aside;

FIG. 83 is a view similar to FIG. 82 showing a further step in the nextstage of manufacturing a pinch valve assembly wherein the second tubularend portion is being emplaced on the length of tubing;

FIG. 84 is a fragmentary view in section of the assembly apparatus andstretched second tubular segment end portion of the pinch valve elementshown in FIG. 83, and with the length of tubing inserted into theapparatus over the central guide rod and through the cluster of spreaderfingers; and

FIG. 85 is a fragmentary view in section of the assembly apparatus withthe second tubular segment end portion of the pinch valve relaxed uponthe length of tubing and the ejector piston moved forward.

DETAILED DESCRIPTION OF THE INVENTION

As used herein and in the claims, descriptive terms such as top, bottom,upper, lower, above, below and the like are understood to refer to afluid delivery set and a rotary peristaltic pump when they are assembledtogether in their intended operative manner and the shaft upon which thepump's perstaltic rotor is mounted is oriented in a substantiallyhorizontal position.

Referring now to the drawings in which like parts are referred to bylike reference numerals, the co-acting apparatus assembly of theinvention is seen in FIG. 1 to comprise a rotary peristaltic pump,indicated generally by the numeral 40, with a pump housing of novelconfiguration, and a fluid delivery set, indicated generally by thenumeral 42, assembled with the rotary peristaltic pump.

The rotary peristaltic pump 40 is shown conveniently mounted on aconventional support pole 90, as is a supply container 91 of an enteralnutritional product. A suitable pole clamp 92 affixed to the back ofpump housing 41 is best seen in top view in FIG. 6.

The assembly of the peristaltic pump and fluid delivery set is shownenlarged in FIGS. 2, 4, 4A, 5, 6, and 6A. The peristaltic pump is shownseparately in FIGS. 3 and 3A. The fluid delivery set is shown separatelyin FIGS. 9-10, and 15-16.

The fluid delivery set 42 provides a continuous fluid pathway from thesupply container 91 of enteral or parenteral fluid to the tube or needleor other device directing the fluid into the body of the patient. Whilein this first embodiment a first end of the fluid delivery set isintegral with a supply container, in alternative embodiments which aredescribed herein a first end of the fluid delivery set is connectable toa supply container, and it is understood that either alternative may beemployed in the practice of the invention described and claimed herein.For example, as shown in FIG. 17 a first end of the fluid delivery setmay be connected to a supply container 101 using a threaded closure 95,or as shown in FIGS. 18 and 19 a first end of the fluid delivery set maybe connected to a supply container 104, 105 by penetrating a membrancein the container or its closure with a spike or cannula 103.

The fluid delivery set 42 is made up of a drip chamber 43 which is shownin FIGS. 1 and 4 partially hidden in a first retentive recess 44 formedin the juncture of the front wall 45 and top wall 46 of the pump housing41. The drip chamber 43 is connected at the inlet thereof to a firstlength 39 of flexible tubing, shown foreshortened. Preferably, the firstand third lengths of flexible tubing 39, 64 are made of polyvinylchloride (PVC) and the second length of tubing 49 is made of anelastically flexible silicone rubber. The first length 39 of flexibletubing is connectable to or integral with the outlet of a supplycontainer and may optionally have a second drip chamber (not shown)and/or a conventional slide clamp 97 assembled therewith. The outlet ofthe drip chamber 43 is connected to the first end 48 of a second length49 of flexible tubing.

The drip chamber 43 is also provided with a collar-like or flange-likefirst retention element 47 press fit or adhesively attached thereto,preferably at the upper end 43a thereof as best seen in FIG. 4A. Thefirst length 39 of flexible tubing is attached to the retention element47 in a telescoping interference fit relationship. The first retentionelement 47, also referred to herein as a drip chamber retention element,shown here is rectangular and nearly square in outer shape and fitscomplementarily into the first retentive recess 44 of the pump housing.If desired, the drip chamber retention element 47 may be made with adifferent geometric shape, such as a triangular or oval or trapezoidalshape, so long as the retentive recess in the pump housing is shapedcomplementarily to receive and retain the drip chamber retentionelement.

The pump housing 41 is preferably molded from an impact resistantpolymer or polymer blend such as an ABS (acrylate-butadiene-styrene)blend or ABS-polycarbonate blend. Extending from the bottom or floor 44aof the first retentive recess 44 of the pump housing is a substantiallyvertical guideway 50 formed in the front wall 45 of the pump housing. Asmay be seen in side view in FIG. 5, the upper part of the front wall 45of the pump housing protrudes forwardly over the lower part, providingfor vertical alignment of the drip chamber 43 and the second length 49of flexible tubing depending therefrom with the pump's peristaltic rotor52 positioned below the drip chamber 43. As seen in FIG. 4, the guideway50 directs the drip chamber 43 downwardly from the first retentiverecess 44 to the connection of the outlet 51 of the drip chamber 43 withthe first end 48 of the second length 49 of flexible tubing.

Referring to FIG. 3, a preferred form of configuration of the pumphousing 41 of the peristaltic pump 40 is shown wherein the firstretentive recess 44 is seen to have a substantially flat floor 44asurrounding the opening to the guideway 50. Two small upstanding bosses71 extend upwardly at the left and right(not shown) back corners of thefloor 44a. The first retention element 47 which supports the dripchamber is preferably made as an inverted hollow box that opensdownwardly as may be seen in FIG. 10A, a view in section taken alongline 10A--10A of FIG. 10, looking up into the open side of the "box".When FIG. 10A is viewed in conjunction with FIG. 4A, which shows across-section of the first retention element 47, it is seen that thisform of retention element has an upper rectangular wall 72 withdepending sidewalls 73 that surround a short centrally located tubularinlet 74 that extends through the upper wall 72, providing forconnection externally to the first length 39 of flexible tubing which isconnectable to, or integral with, a supply container. Concentricallysurrounding the tubular inlet 74 that extends slightly through the upperwall 72 and is surrounded by the sidewalls 73 is a foreshortenedcylindrical sleeve portion 75 integrally formed with the upper wall 72.The cylindrical sleeve portion 75 serves as a support for the dripchamber 43, the upper end 43a of which, as indicated in FIG. 4A, istelescoped over the cylindrical sleeve portion 75 and press fit oradhered thereto.

It is further preferred that a small flange-like tab 77 be provided onthe forward side of the sidewall 73 at the lower edge thereof. Such aflange-like tab is found to be readily grasped between the thumb andforefinger providing for convenient positioning or removal of the firstretention element 47 and the attached drip chamber 43 and second length49 of flexible tubing when mounting or removing the feeding set 42 fromthe pump housing 41.

The peristaltic pump rotor 52, as best seen in FIGS. 3 and 5, isconventional, having a plurality of rollers 53, for example, two tofour, three being a practical number, that extend parallel to the axisof rotation of the rotor between opposing disc-like end face members 57and are equi-angularly disposed along a circumferential line about theaxis of rotation of the rotor. Preferably the rollers 53 are eachrotatable upon an axial rod or pin (not shown) which extends between theend face members 57. If desired, the rollers 53 may be fixed and notrotatable, but if fixed, will require more power to rotate the rotoragainst the second length 49 of flexible tubing held thereagainst undersufficient tension to provide peristaltic pumping action, and increasedwear of the fixed rollers can be expected. The end face members 57 aresupported axially on a shaft that is driven by a pump motor (neither theshaft nor the pump motor is shown), the pump motor being mounted withinthe pump housing 41 and the shaft extending forwardly through the frontwall of the pump housing to support and rotate the peristaltic rotor 52.The pump motor is provided electrical power through a conventionalelectric appliance cord 93. A control knob 94 for selecting the fluiddelivery rate is provided on the front of the pump housing.

Referring now to FIGS. 4, 9 and 10, the second length 49 of flexibletubing is wrapped down, around and against the peristaltic rotor 52 andis held under tension against the rollers 53 of the rotor 52 as thesecond length 49 of flexible tubing is brought back up the other side ofthe rotor to a connection of the second end 60 of the second length 49of flexible tubing with a first leg 61 of a second retention element 56,referred to hereafter as a retention/connector element. Theretention/connector element 56 is retained in the second retentiverecess 55 of the pump housing when the peristaltic pump and fluiddelivery set are assembled together. The second leg 62 of theretention/connector element 56 is connected to the first end 63 of athird length 64 of flexible tubing. The connection of the respectiveends of the second length 49 of flexible tubing to theretention/connector element 56 and to the outlet of the drip chamber 43is made by placing the tubing ends on the one hand, and theretention/connector or drip chamber outlet on the other hand, in amale/female, or telescoping, relationship, or interference fit, and ifdesired, using adhesives, welding, etc., to secure the joint so-made.

The retention/connector element 56, is retentively but replaceably heldin the second retentive recess, or receptacle, 55 which is formed in theprotruding upper part of the front wall 45 of the pump housing 41 and issubstantially vertically aligned with the side of the peristaltic rotor52 opposite the side aligned with the drip chamber 43. As best seen inFIG. 3A, a notch or slot 58 extending through the floor 59 of theretentive recess 55 and opening to the front of the housing wall 45admits the vertical first leg 61 of the retention/connector element 56.

In a preferred form shown in greater detail in FIGS. 23-28, theretention/connector element 56 is preferably molded into a substantiallyhollow tubular form and the continuous fluid pathway 54 as it extendstherethrough forms about a right angle bend, whereby theretention/connector element 56 has first and second legs 61 and 62, thatare joined at about a right angle. The fluid pathway 54 through theretention/connector element 56 has preferably about the samecross-sectional area throughout as the lumen of the lengths of flexibletubing connected thereto so that there is substantially no constrictionof fluid flow around the right angle bend. The bend in the preferredretention/connector element has a radius, at the location indicated by"R" in FIG. 25, of less than about 0.9525 cm.(0.375 inch), preferablyless than about 0.635 cm.(0.25 inch) in order to fit retentively intothe recess 55. Comparative testing has indicated that theretention/connector element of the fluid delivery set disclosed hereinis more securely attached to the rotary peristaltic pump disclosedherein than the analagous prior art retention device/perstaltic pump ofthe prior art shown in FIGS. 21 and 22.

In order to have good retention of the retention/connector element 56 inthe second retentive recess or receptacle 55 so that accidental total orpartial removal of the fluid delivery set 42 from the pump housing 41 isdifficult and thus unlikely, with the retentive recess 55 having anopening with a vertical height, as represented by dimension "X" in FIG.5, of about 1.12 cm.(0.44 inch), the angle of the bend, as representedby the angle "β" in FIG. 27, in the retention/connector element 56 mayvary from a right angle by not more than about plus or minus 11.8degrees, or at a maximum of about 12 degrees variation. Thus, the angle"β" of the bend may vary from about 78 to about 102 degrees, but ispreferably between about 85 to about 95 degrees for ease in insertionand removal of the retention/connector element 56 and also for goodinterlocking thereof with the retentive recess 55. Comparative testinghas indicated that the retention/connector element 56 of the fluiddelivery set disclosed herein is more securely attached to the rotaryperistaltic pump disclosed herein, than the analogous prior artretention device rotary peristaltic pump of the prior art shown in FIGS.21 and 22.

A highly preferred feature of the retention/connector element 56 is aforeshortened retention tab 65 that extends laterally from theretention/connector element 56 at about the level of the right anglebend and in a direction opposed to the second, i.e., horizontal, leg 62.As best seen in FIGS. 8 and 8A, the retention tab 65 serves to helpretain the retention/connector element 56 in the second retentive recess55 of the pump housing and also helps support the retention/connectorelement 56 on the floor 59 of the second retentive recess and prevent itslipping down through notch or slot 58 in the floor 59. Preferably, theretention/connector element 56 is also provided with a forwardlyextending handle or tab 66 for grasping that is conveniently graspedbetween the thumb and forefinger when inserting the retention/connectorelement 56 into, or removing it from, the second retentive recess 55.The handle or tab 66 for grasping is also located at about the level ofthe right angle bend in retention/connector element 56 and extends atabout a right angle to each of the first and second legs 61,62 and tothe retention tab 65.

In FIGS. 23 to 28 retention/connector element 56 is shown with the firstleg 61 having a smaller outer diameter over which the second end 60 ofthe second length 49 of flexible tubing is to be telescoped inconnecting the two, as shown in FIGS. 9, 10, 15 and 16, and the secondleg 62 is shown with a larger inner diameter into which the first end 63of the third length 64 of flexible tubing would be telescoped in makingthe connection therebetween. This is merely a matter of choice andeither connection may be made with the flexible tubing being the inneror outer member of the connection.

Alternative embodiments 56a-56f of retention/connector elements whichmay be used in the practice of the present invention and thatincorporate a right angle bend within the retention/connector elementare shown in FIGS. 29 to 34 with various shapes and sizes andorientations of the tabs 66b-66f for grasping the retention/connectorelement corresponding to tab 66, or absence thereof as shown inembodiment 56a in FIG. 29, and with a variation in the shape of theretention tab 65a in FIG. 29 corresponding to retention tab 65. It isunderstod that the retention tab may take a wide variety of shapes solong as there is provided a complementary cavity in the pump housingwith retention characteristics that facilitate ready insertion andremoval of the retention/connector element.

Retention/connector elements that have only one leg but have variousshaped retention tabs are depicted in FIGS. 35-38. The approximate rightangle bend in the fluid pathway needed to fit into the second retentiverecess 55 and horizontal guideway 67 of the pump housing 41 is made inthe third length 64 of flexible tubing which is bent immediatelyadjacent the connection thereof to the retention/connector element56g-56j. Such bends in the third length 64 of flexible tubing are shownin FIGS. 35-38. The flexible tubing must be of material that does notunduly restrict fluid flow from a peristaltic pump when bent at about aright angle over a radius of less than about 1.25 cm and preferably notwhen bent over a radius of about 0.9525 cm (0.375 inch). However, it isunderstood that a retention/connector element used for connecting thesecond and third lengths of flexible tubing must have a retention tab65g-65, extending substantially normal to the vertical leg 61g-61, tocomplementarily engage a retentive recess 55 in the pump housing 41.Most preferably the retention tab has a flange 79 extendingsubstantially normally therefrom to mate with a retentive recess in thepump housing.

When the fluid delivery set is assembled with the peristaltic pump, thethird length 64 of flexible tubing extends from the connection of thefirst end 63 thereof with the second leg 62 of retention/connectorelement 56 along horizontal guideway 67 formed in the front wall 45 ofthe pump housing 41. As best seen in FIG. 3A, the guideway 67 isconnected to and leads from the second retentive recess 55 to a lateralside of the front wall 45 of the pump housing 41, here the closestlateral side. In a preferred embodiment, the third length 64 of flexibletubing extends horizontally from the retention/connector element to alateral side of the front wall of the pump housing and thereafterextends to an adapter or connector 64a for connecting the second end ofthe third length of flexible tubing to a device, such as a feeding tubeor needle, leading into the body of a patient. Some examples of suchdevices are, in enteral administration: a feeding tube 69 seen in FIG.1, and feeding tube 69a seen in FIG. 19, each extending through agastrostomy 70 into the stomach 174; a nasogastric tube 171 leading downthe esophagus into the stomach 174 as seen in FIG. 17; a jejunal feedingtube 186 extending through a jejunostomy 173 to the jejunum 187 as seenin FIG. 18; or, in parenteral administration: a needle or other tubularinlet 88 leading into the vein 87 of a patient as seen in FIG. 20. Asalready stated above, it is also understood that the third length oftubing may be integral with a device suitable for insertion into thebody of a patient.

Positioning the guideway 67 horizontally to bring the third length 64 offlexible tubing out horizontally from the pump housing 41 is believed tobe preferred by care givers over a disposition of the flexible tubing inan upward arc as it emerges along a guideway from a pump housingaccording to the prior art as seen in FIGS. 21 and 22. Care givers haveless difficulty with maintaining the present apparatus in carefree,uncomplicated working order, especially when caring for restlesspatients.

The retention/connector element used in the practice of the presentinvention may also take one of the forms 56g-56j shown in FIGS. 35 to 38in each of which the right angle bend of the fluid pathway is achievedin a segment of the third length 64 of flexible tubing immediatelyadjacent the retention/connector element instead of within theretention/connector element. In using the retention/connectors 56g-56jof FIGS. 35 to 37, the third length 64 of flexible tubing must be bentwithin the horizontal guideway 67, but not bent so sharply as to undulyrestrict fluid flow through the bend. In using the retention/connectorelement 56j of FIG. 38 the third length 64 of flexible tubing isdirected forwardly horizontally and special care should be taken toavoid unsupported tubing bending downwardly too sharply so as to blockthe flow of fluid therethrough. The use of retention/connector elementswith the right angle bend within the retention/connector element ispreferred.

If desired, however, the assembly of the invention having aretention/connector element 56k in the alternative form shown in FIG. 39may be employed. In retention/connector element 56k the right angle bendof the retention/connector element projects forwardly and horizontallyfrom the second retentive recess 55 and not towards the horizontalguideway 67. As seen in the fragmentary sectional views of FIGS. 40 and41, the second end 60 of the second length 49 of flexible tubingconnects to the lower leg 61k of the retention/connector element 56k andthe retention/connector element 56k with its retention tab 65k fitsinterlockingly into the second retentive recess 55 with the other leg62k of the retention/connector element 56k projecting forwardly and indog-legged shape into a second right angle bend with a third leg 62k'extending upwardly. The first end 63 of third length 64 of flexibletubing telescopes over the third leg 62k' in making connection to thisform of retention/connector element 56k, and the third length 64 offlexible tubing is allowed to arch over and down to the connection tothe patient.

In assembling the fluid delivery set 42 with the peristaltic pump 40,the second length of flexible tubing 49 is slipped laterally into theguideway 50 via a vertically extending slot 50a (see FIG. 8) and thenthe drip chamber 43 is slid down into the guideway from the top of thepump housing until the first retention element 47 is seated in the firstretentive recess 44 with the lower edge of the sidewall 73 at the backside of the recess retentively situated between the bosses 71 and theback wall of the first retentive recess 44, as may be seen in crosssection in FIG. 4A.

In FIG. 4 the fluid delivery set 42 is shown assembled with the pumphousing 41 with the second length 49 of flexible tubing under sufficienttension between the first retentive recess or receptacle 44 and thesecond retentive recess or receptacle 55 so that the second length offlexible tubing 49 is under tension and is pressed against the rollersof the peristaltic rotor 52 to facilitate peristaltic pumping when theperistaltic rotor is rotated.

As may be seen in FIG. 3 and FIG. 4A, the guideway 50 of the retentiverecess 44 is very preferably provided with a substantially verticalgroove 81 in the sidewall 76 of the guideway with an aperture 81a formedin the wall of the groove 81, the aperture opening to the interior ofthe pump housing 41. A like groove and aperture (not shown) is providedon the opposing side of the guideway 50 and the aperture aligned withaperture 81a so that a light or signal source (not shown)within the pumphousing 41 may be directed through the opposing apertures, and the dripchamber 45 therebetween, to a conventional detector such as a photocell(not shown) for the detection of drops of fluid moving through the dripchamber 43. Electronic means within the pump housing may be programmedto halt the pumping operation if a continuous series of drops of fluidare not detected. Use of such a system is highly preferred as a goodprecautionary practice. If desired, an aperture 67a between thehorizontal guideway 67 and the vertical guideway 50 may be provided, asshown in FIGS. 3 and 3A, to facilitate molding of the pump housing.

Turning again to FIGS. 2 and 3, and particularly to FIG. 3A, and havingreference also to the sectional views in FIGS. 7, 8 and 8A, the secondretentive recess 55 is preferably formed with flanges 78,78a at thefront edge of the recess and most preferably one of these flanges isformed at the front edge at each side of the slot or notch 58 for thebetter retention of the retention/connector element 56. As seen moreclearly in FIG. 8A the retention tab 65 of the retention/connectorelement is preferably formed with a flange portion 79 on the undersidethereof to fit complementarily behind the flange 78 on the left side ofthe slot 58 as viewed from the front of the housing 41. The secondretentive recess 55 is also provided with sufficient lateral depth tothe left of the slot 58 to accommodate the retention tab 65 behind theflange 78 and recess wall, as may be seen illustrated in FIG. 8. In thissetting the retention tab 65 is much preferred for the positiveinterlocking achieved with the flange or flanges 78, 78a, of the secondretentive recess.

It is preferred that a pinch valve 80 be employed as a component of thefluid delivery set as a precaution against unintended and uncontrolledfluid flow in the event the fluid delivery set 42 is dislodged from thepump housing whereby the rollers 53 of the peristaltic pump rotor 52 donot control fluid flow. Referring to FIGS. 2-5 and 12-16, a pinch valve80, such as that depicted in FIG. 12, is shown mounted on the secondlength 49 of flexible tubing between the peristaltic rotor 52 and thesecond retentive recess 55, which is a preferred location for the pinchvalve. However, it should be understood that the pinch valve may belocated between the outlet of the drip chamber and the peristaltic rotorif desired. The tension on the second length 49 of flexible tubingshould also be sufficient to unkink or unpinch the pinch valve 80sufficiently for substantially unimpeded flow of fluid therethrough andthe pinch valve should be responsive to the level of tension that issufficient for proper action of the peristaltic rotor.

As indicated, it is preferred to employ with the fluid delivery set ofthe invention a pinch valve that may be used to pinch shut the flexibletubing at some point along the fluid pathway, and preferably the pinchvalve is automatic in operation and responsive to tension, especiallythe lack thereof. The preferred pinch valves pinch or kink the flexibletubing sufficiently to block fluid flow through the flexible tubing whenthere is not sufficient tension on the flexible tubing where the pinchvalve is located. Thus, if the fluid delivery set is dislodged from thepump housing or the fluid delivery set is not properly assembled withthe pump housing and the flexible tubing is not pressed against therollers of the peristaltic rotor, the pinch valve will substantiallyprevent flow of fluid through the fluid delivery set.

A preferred form of pinch valve element is shown in FIG. 12 and consistsof a single member 80 formed of elastically flexible polymeric materialsuch as silicone rubber like, or similar to, the silicone rubberemployed in the second length of flexible tubing of the fluid deliveryset, but having foreshortened cylindrical tubular segment end portions82, 83 connected by a nearly hemi-cylindrical shank portion 84integrally formed therewith. In a working embodiment the inside diameterof the pinch valve element 80 prior to assembly is actually less thanthe outside diameter of the second length of flexible tubing of thefeeding set 42 which results in good position retention on the length 49flexible tubing when assembled. In the working embodiment the pinchvalve element is die cut from the same kind of flexible tubing that isemployed as the second length of flexible tubing in the fluid deliveryset.

Referring now to FIGS. 13 and 14, the pinch valve element 80 isinstalled on flexible tubing such as second length 49 with one end ofthe pinch valve element located a distance "E" from the end of thetubing such that the other end of the pinch valve element is located adistance B from the end of the tubing sufficient to facilitateconnecting the tubing to another component. The tubular segment endportions 82, 83 of the pinch valve element are spaced apart a distance"C" along the flexible tubing 49 whereas the shank portion 84 assumes alength "D" when not under tension, the length "D" being sufficientlyshorter than the length "C" to bend over and pinch the tubing shut whennot under sufficient tension to stretch the shank portion 84. As anexample, with a flexible silicone rubber tubing of 0.33 cm. (0.131 inch)inner diameter, 0.51 cm. (0.199 inch) outer diameter and a wallthickness of about 0.086 cm. (0.034 inch), and with a pinch valve 80element die cut from the same type of tubing having the inner edges ofthe tubular end portions 82, 83 spaced apart by a shank portion about0.51 cm. (0.199 inch) in length when not under tension, the inner edgesof the tubular end portions 82, 83 should be separated by a distance ofabout 2.0 cm. (0.80 inch) when installed telescopically on the secondlength 49 of flexible tubing, in order to obtain a desired tightness ofpinching or kinking to block fluid flow. For a given elasticallyflexible tubing, the dimensions are very important to obtain the desiredvalve action with good opening and sufficiently positive shut off. Thelength of the flexible tubing embraced between the tubular segment endportions of the pinch valve element is especially important to getsufficient doubling over for a sharp bend, but not so much as to form alooser loop. This can be determined empirically by trial and error for agiven size flexible tubing made of a material with a given modulus ofelasticity.

In FIG. 43 there is shown an alternative pinch valve element 80a havinga rectangular substantially planar shank portion 84a connectingrectangular substantially planar end portions 82a,83a. The end portions82a,83a each have a concave surface adapted to fit conformingly againstthe outer cylindrical surface of the flexible tubing 49 and are bondedor cemented thereto, as seen in FIG. 42, after bending the flexibletubing section encompassed by the pinch valve element so that attachmentcan be made with the length of the shank portion 84a much shorter thanthe length of encompassed flexible tubing section in the resulting pinchvalve.

In FIG. 4 element 8s seen another alternative pinch valve element 80bthat is shaped like the capital letter "I" and formed of a flat,sheet-like, elastic, flexible, polymeric material. The pinch valveelement 80b is attached to the flexible tubing 49 by wrapping the widersheet-like end portions 82b, 83b substantially around the flexibletubing and bonding or cementing them thereto as seen in FIG. 44 atlocations spaced further apart longitudinally of the flexible tubing 49than the length of the shank portion 84b whereby the flexible tubingsection encompassed by the end portions 82b,83b is doubled over andpinched shut as shown in FIG. 44 when the flexible tubing 49 is notunder longitudinal tension.

Yet another alternative pinch valve element 80c is seen in FIG. 47 inwhich a shank portion 84c having an arcuate cross section ofhalf-cylinder or hemi-cylindrical shape joins arcuate end portions82c,83c that are accurately slotted on the concave surface that is matedwith the cylindrical outer surface of the flexible tubing 49 as shown inFIG. 47A. As in the case of the other pinch valve embodiments depictedherein, the flexible tubing 49 is bent during the assembly of the pinchvalve seen in FIG. 46 so that the encompassed section of the flexibletubing will be much longer than the shank portion 84c of the pinch valveelement. Thermal bonding or cementing of the pinch valve element endportions 82c,83c to the flexible tubing 49 completes the manufacture ofthe pinch valve shown in FIG. 46.

Still another alternative pinch valve element 80d is shown in FIG. 49 inwhich a shank portion 84d and end portions 82d, 83d are all part of onehemi-cylindrical sleeve-shaped piece of elastically flexible polymericmaterial which is shown in FIG. 48 attached, for example by bonding oran adhesive, to flexible tubing 49 to form another embodiment of thepinch valve of the invention. Again, in bonding or cementing the shankportion 84d to the flexible tubing 49, the tubing section encompassed bythe pinch valve element is bent sharply so that the end portions 82d,83dof the pinch valve element will be attached at locations longitudinallyspaced along the flexible tubing 49 such that tubing section encompassedby the pinch valve element will be substantially longer than shankportion 84d to provide the tension responsive valve effect.

Another embodiment of a pinch valve element 80e is depicted partly, andalso entirely, assembled with a length of flexible tubing in FIGS.50-52. Pinch valve element 80e comprises foreshortened tubular segmentend portions 82e,83e joined by a strip or rod-like shank portion 84e.The end portion 82e is initially insert molded to the flexible tubing49, as is positioning collar 86 which is spaced apart from the endportion 82e by the intended length of encompassed flexible tubingsection. The section of the flexible tubing 49 positioned between thetubular segment end portion 82e and positioning collar 86 is then bentsharply and tubular segment end portion 83e is slipped over the adjacentend of flexible tubing 49 until the end portion 83e is against thepositioning collar 86 where the tubular segment end portion 83e isbonded or cemented in place, thus forming the pinch valve depicted inFIG. 51. As shown in FIG. 52, when the tubing 49 is placed undersufficient longitudinal tension, shank portion 84e yields andencompassed flexible tubing section straightens out sufficiently thatfluid may flow therethrough.

Referring now to FIGS. 53-55, another embodiment of a pinch valveelement 80f is seen having closed loop or eye-like end portions 82f,83fjoined by a narrower shank portion 84f. An end portion 82f of the pinchvalve element is emplaced telescopically around the flexible tubing 49 aselected distance from an end thereof and the flexible tubing is thenbent sharply between the position of the end portion of the pinch valveelement 82f and the nearest end of the flexible tubing and the other endportion 83f is telescopically emplaced around the flexible tubing to aposition defining an encompassed flexible tubing section and the endportions are bonded or cemented in place. For example a room temperaturevulcanizing silicone polymer composition may serve as a suitableadhesive to be inserted along or just under the margins of the pinchvalve element end portions. The completed pinch valve is tensionresponsive, kinking shut when not under tension as seen in FIG. 54 andbeing openable under sufficient tension as depicted in FIG. 55.

Referring now to FIG. 56, still another form of tension responsive pinchvalve is made by molding a sharply bent piece of a highly elasticspringy material, such as metallic spring wire 181, or a suitablepolymeric material, in the wall 182 of a length of flexible tubing. Thememory of the sharply bent springy material causes the flexible tubingto be pinched shut when there is not enough longitudinal tension appliedto the flexible tubing. As seen in section in FIG. 57, the wall of thetubing is made thicker along a longitudinal side to accommodate themolding of the high elastic springy material therewith. In yet anotherform of tension responsive pinch valve 80h a sharply bent piece of ahighly elastic springy material, such as a spring wire 181, or asuitable polymeric material, may also be molded onto or adhered onto,the outside of the wall 183 of the flexible tubing as indicated insection view in FIG. 57A.

Utilizing another mode of action a tension responsive pinch valve ismade using a springy pinch valve element that is pre-formed with amemory that causes the ends of the valve element to twist sufficientlyto close the lumen of a flexible tubing telescopically embraced by thevalve element. Such a pinch valve element is identified by the referencenumeral 80i in FIG. 58 where the pinch valve element, having tubularsegment end portions 82g,83g and a shank, in the form of a plurality oflongitudinal ribs 84g that are helically twisted, connecting the endportions, is shown assembled telescopically on a length of a length offlexible tubing. During assembly, the pinch valve element 80g is placedunder longtidinual tension to straighten the longitudinal ribs 84g whilethe length of flexible tubing 49 is inserted through the pinch valveelement and bonded or adhesively attached thereto while the longitudinaltension on the pinch valve element 80g is maintained. On relexing thelongitudinal tension on the assembled pinch valve, the pinch valveelement 80g twists the encompassed section of the flexible tubing,kinking it shut. Under tension, the resulting pinch valve untwists tounpinch the flexible tubing, permitting fluid passage therethrough.

It is thus evident that many embodiments of the pinch valve elementemployed herein may be made in many different forms from elasticallyflexible polymeric material and shaped to have two end portionsconnected by a shank portion. The end portions must be attachable to theflexible tubing of which the pinch valve is formed and must be attachedwith the end portions spaced apart a greater linear distance along theflexible tubing than the length of the unstretched shank portion of thepinch valve element, a relative distance in the range of about 4:1,varying only slightly as will at once be apparent, according to theelastic yield strength of the shank portion of the pinch valve elementand the bend strength modulus of the flexible tubing, so that theencompassed tubing section will be pinched or kinked sharply enough bythe pull of the shank portion when the pinch valve is not under tensionthat shut-off or occlusion of fluid flow through the flexible tubingwill take place.

In all embodiments the shank portion must deform elastically underappropriate tension for the setting in which the valve is used that thepinch valve will open under longitudinal tension applied to the flexibletubing for the operations or procedures being carried out, yet closewhen the tension is released or absent.

A tension responsive pinch valve of the type shown in FIGS. 11-16 hasbeen assembled by emplacing the pinch valve element upon a length oftubing using the assembly apparatus disclosed herein which has utilityfor placing a flexible, and at least somewhat elastic, foreshortenedtubular segment telescopically upon and near an end of a length oftubing having an outer diameter substantially the same or greater thanthe inner diameter of the tubular segment. A very important aspect ofthe assembly apparatus disclosed herein is the capacity to eject theassembled combination of a flexible tubular segment and a length oftubing from the assembly apparatus without displacing the flexibletubular segment longitudinally along the length of tubing.

For the purposes of the specification and claims it should be understoodthat the front side or surface, also referred to herein as a firstsurface, of the assembly apparatus is the side or surface into which thelength of tubing is inserted for emplacement of a flexible tubularsegment thereon, while the back or rear side or surface is opposite thefront side or surface. A forward motion is a motion towards the frontside or surface as here defined, while a rearward motion or extension istaken in the opposite direction.

As seen in the exemplary embodiment shown in FIGS. 59-61, and the viewin section in FIG. 63, along with the exploded view in FIG. 64, thepresent assembly apparatus is made up of a body portion, indicatedgenerally by the reference numeral 341; which may if desired have a basesupport portion 342, which may be secured to a base plate 343, forexample by bolts 403, if desired, for stability during use. It is to beunderstood that the support structure may take any suitable shape andorientation and the parts thereof attached together by any suitablemeans such as welding or clamping.

As seen in FIG. 64, the exemplary assembly apparatus consists mainly ofthe body portion and suitable base or support portions, in addition to asub-assembly, indicated generally by the reference numeral 330, a coverplate 347, a first retainer ring 352, a control ring 357, a secondretainer ring 366 and a rear support element 374. In the assembledapparatus the sub-assembly 330 having controllably spreadable andretractable spreader finger portions is positioned in a cylindrical bore344 that extends through the body portion 341 from the first, or front,face to the second, or rear, face and the other components are attachedin the sequence and positions indicated, using screws and bolts 402,405, 406, 407, 408 or other suitable fastening means.

The combination of the sub-assembly 330 with spreader finger elements339, as seen in exploded view in FIG. 68, together with the cover plate347 and the control ring 357, when mounted in the body portion 341comprises a mechanical means for assembling a tubular segment with alength of tubing. Moreover, an integral part of the sub-assemblypositioned concentrically and reciprocably within the mechanical meansfor assembly constitutes means for ejecting an assembly of a tubularsegment with a length of tubing as will be further described herein.

The means for assembly which includes mechanical means for spreading andretracting the spreader finger elements 339 is described in detail belowand is comprised primarily of: (1) a substantially cylindrical rotatablesleeve 149, that is rotatable in the cylindrical bore 344 of the bodyportion 341 of the apparatus; (2) a control ring 357 for rotating therotatable sleeve 149; (3) a disc-like member 354 having radially, i.e.,spirally, extending spiral guideways 360 formed therethrough and beingmounted co-axially upon a first end of the rotatable sleeve 149 in anannular recess; and (4) at least three spreader finger elements,indicated generally by the numeral 339, that are supported by acombination of the disc-like member 354 and a cover plate 347 andradially spread or retracted by co-action of the disc-like member andthe cover plate with the spreader finger elements.

The ejector means comprise: (1) a reciprocable piston 362, depicted inFIGS. 67 and 68 as part of the assembly apparatus shown in differingstages of the assembly process; (2) an ejector block 368 or 368a asdepicted in FIGS. 65 and 66; and (3) ejector arms 371, in addition tothe rotatable sleeve 149 in the cylindrical passageway of which thepiston 362 is reciprocable.

The subassembly identified by reference character 330 in FIGS. 64, 68,70 and 71, includes the substantially cylindrical rotatable sleeve 149with a cylindrical passageway extending therethrough and into which thereciprocable piston is positioned co-axially, indicated generally by thenumeral 362. The reciprocable piston has a recess in one end into whichthere is positioned co-axially an ejector block such as ejector blocks368 and 368a depicted in FIGS. 65 and 66. The ejector block has aplurality, in this example three, longitudinal slots 370 therein and onwhich are pivotally mounted, using pins 371b, ejector arms 371substantially parallel to the longitudinal axis of the piston 362,bearing in mind that when the assembly apparatus is fully assembled, thepiston is co-axial with the bore 344 through the body portion 341.

In a recess in the first end 365 of the piston 362 there is mounted inany suitable manner an ejector block 368, such as the ejector blockshown in FIG. 65. The ejector block shown in FIG. 65 has a rearwardlyextending tongue-like portion 338 that fits into a complementaryborehole or passageway 336 in the piston 362 and is secured by asetscrew 337. The overall longitudinal length of the ejector block usedin the assembly apparatus determines the distance from the end of thelength of tubing where the tubing segment will be emplaced during theassembly process.

In assembling a pinch valve element with two tubular segments as endportions it is necessary to assemble each tubular end portion with agiven length of tubing in a separate operation in which an assemblyapparatus is used with an ejector block having the appropriate length.Thus a shorter ejector block such as that shown in FIG. 65 would be usedto emplace the first tubular segment, e.g. 82, while a longer ejectorblock 368a, as shown in FIG. 66, would be used in assembling the secondtubular segment, e.g. 83, with the length of tubing to get the properpositioning of the tubular segments and achieving also the properspacing longitudinally along the flexible tubing between the tubularsegments. The ejector block 368a is provided with a forwardly projectingaxial extension 338b that has a large enough cross-section to serve as astop for the length of tubing, but is small enough to facilitate use ofthe coil spring 363 to make the piston 362 recoil after the ejectionstep.

In assembling the present apparatus the subassembly 330 seen in FIG. 64is made up by selecting an ejector block 368 (or alternatively ejectorblock 368a of FIG. 66) of suitable dimensions, such as the ejector blockdepicted in FIG. 65, and positioning a plurality of pivotal ejector arms371 in respective slots 370 formed in the sides of the ejector block 368where the ejector arms are pivotally retained by pins 371a that passthrough the walls of the slots and through the ejector arms near a firstend 333 of each arm. The number of ejector arms 371 and complementaryslots 370 employed is preferably at least three to match the number ofspreader finger elements 339. The ejector arms 371 are orientedsubstantially parallel to the axis of the ejector piston 362. Therearward projecting tongue-like portion 338 of the ejector block 368 isinserted into the axial borehole 336 in the end 365 of the piston 362and secured with a set screw as shown in FIG. 63.

Referring now to FIGS. 63 and 68, an elongated central guide rod 369 isinserted into and secured in any suitable manner in a longitudinal axialborehole 334 in the free end of the ejector block 368, or, in alongitudinal axial borehole 334a of the axial extension 338b of ejectorblock 368a if the longer extension block is part of the subassembly.

Turning again to FIGS. 67 and 68, an elastic annular member 372, whichmay be a conventional "O"-ring, is placed around the ejector arms 371 atabout mid-length, for example at notches 335 in the arms, to retain themclustered together around the spreader finger portions 358 in the finalassembly.

Adjacent the second end 332 of each of the ejector arms 371 is anelongated longitudinally extending slot 373 formed therethrough. Througheach of the slots 373 a respective leg portion 356 of a spreader fingerelement 339 extends radially outward from the line of the axis of thepiston 362. As seen in FIGS. 68, 69 and 71, the spreader finger elements39 are "L"-shaped, each with a leg portion 356 and a thin finger, i.e.,finger portion, 358. To accommodate reciprocal movement of the ejectorarms 371 along the axial line during an ejection step withoutinterfering with the normal function of the spreader finger elements339, the leg portion 356a that joins the finger portion 358 to the legportion 356 in each element is preferably made thin enough so that thesides of the slot 373 do not bind against the leg portion 356a.

The means for assembling a tubular segment telescopically upon a lengthof tubing form part of the subassembly 330, which includes the spreaderfinger elements 339. The mechanical means for radially spreading thespreader finger portions include the disc-like member 354 as well as therotatable sleeve 149 on which the disc-like member 354 is mounted. Thecover plate 347 with its radial channels 355, while not part of thesubassembly 330, is also an essential part of the mechanical means forspreading and retracting the spreader finger portions in cooperationwith the disc-like member 354 and its spiral guideways 360.

As best seen in FIG. 69, each spreader finger element 339 is providedwith a guide pin 359 that extends laterally from about mid-length of theleg portion 356 so as to extend into a spiral guideway 360 of theimmediately adjacent disc-like member 354. With the spreader fingerelements 339 restricted by the radial channels 355 of the cover plate347 so that they cannot rotate, rotation of the disc-like member 354provides cam-like action as the guide pins 359 are forced to slide alongthe respective spiral guideways 360, moving the spreader finger elements339, and their finger portions 358, radially outward or inward,depending on the direction of rotation.

In further assembling the subassembly 330 of FIG. 64, as seen in FIG.70, a coil spring 363 is slid over the cluster of ejector arms 371,followed by the disc-like member 354 preparatory to attaching it as bythreaded fasteners 401 to the annular end face of the rotatable sleeve149, after sliding the piston 362 further into the passageway of therotatable sleeve 149, as seen in FIG. 71. Also seen in FIG. 71 are thespreader finger elements 339 positioned with the finger portions 358clustered concentrically inside the cluster of ejector arms 371 andaround the central guide rod 369.

The subassembly 330 seen in FIG. 64 and largely contained within therotatable sleeve 149 can now be inserted into the body portion 341 fromthe first or front side 345 thereof into the bore 344 and partiallyextending beyond the second or rear side 346 of the body portion 341 andpositioned as seen in FIG. 63, so that the cover plate 347 can beattached by threaded fasteners 402, preferably using a locating pin 404to align the grooves in the back side of the cover plate (describedbelow) in the required operative orientation. The inside face, i.e. theback side, of the cover plate 347, as seen in FIG. 72, is formed withradial channels 355 in which the respective leg portions 356 of thespreader finger elements 339 are reciprocable when positioned thereinwith the cover plate attached with the inside face turned face to facewith the disc-like member 354. The radial channels 355 formed in theinside face of the cover plate 347 and with the leg portions 356 ofspreader finger elements 339 postioned therein are, of necessity, opentoward the disc-like member 354 so the guide pins 359 can extend into,and slide along, the spiral guideways 360.

Referring again more particularly to FIGS. 63 and 64, the body portion341 is seen to encompass the cylindrical bore 344, which is ofrelatively large diameter compared to the body portion, and extends fromthe first surface or side 345 to the second surface or side 346 of thebody portion. While the assembly apparatus is shown in the drawingfigures supported upon a base with the assembly apparatus oriented toreceive an end portion of the length of tubing disposed substantiallyhorizontally during the assembly procedure, it is to be understood thatthe base may be modified, if desired, to support the apparatus with thebore tilted upwardly at any angle to receive the length of tubing,including facing substantially vertically upward, without departing fromthe scope of the invention. In such event the first or front side of theapparatus as here described would be the upper or top side or surfaceand the second or back or rear side would be the lower or bottom side orsurface of the assembly apparatus.

The first surface 345 of the body portion 341 is substantially coveredby the circular cover plate 347 with an aperture 347a located at thecenter thereof, while the second surface 346 of the body portion 341 isfaced with a first retainer ring 352 that has a slightly smaller innerdiameter than the diameter of the cylindrical bore 344. The cover plate347 and the first retainer ring 352 are fastened to the body portion341, for example, by screws 402, 405, respectively, but it is to beunderstood that any suitable means of retaining these components intheir relative operable positions may be employed.

As best shown in FIGS. 63 and 64, within the cylindrical bore 344, asindicated above, is a rotatable substantially cylindrical sleeve or tube149, having a first end 350 and a second, smaller, end 351. Therotatable sleeve 149 is retained in the cylindrical bore 344 by a flangeor shoulder 353 of the rotatable sleeve which mates with, or fitsagainst, the radially inner portion of the first retainer ring 352 inthe vicinity of the second surface 346 of the body portion 341 and aradially outer, forwardly projecting, flange portion 350a of the firstend of the rotatable sleeve is retained by the cover plate 347. Whilethe first end portion 350 of the rotatable sleeve 149 has a larger outerdiameter than the second end portion 351, hence the flange or shoulder353, the inside diameter of the cylindrical passageway through therotatable sleeve is uniform, and the rotatable sleeve will be referredto herein as substantially cylindrical. The second end 351 of therotatable sleeve 149 is disposed outside of the cylindrical bore 344 andthe first retainer ring 352 and is concentrically surrounded by arotatable control ring 357, preferably of slightly greater diameter thanthe first retainer ring 352 and preferably having a knurled perimetersurface and/or a lever 361 extending therefrom for easy manipulation.The control ring 357 is bolted or otherwise attached in any suitablemanner to the rotatable sleeve 149.

The first end 350 of the rotatable sleeve 149 has a recessed annular endface, having a perimeter flange 350a, as indicated. In the annularrecess radially inward from the flange 350a is fitted the disc-likemember 354 that is bolted or otherwise fixedly attached to the end faceand has a central aperture 354a the same diameter as the centralaperture 347a of the cover plate 347, but slightly smaller than theinner diameter of the passageway through the rotatable sleeve 149. Therotatable disc-like member 354 has one face contacting the face of theannular recessed end of the rotatable sleeve 149 to which it is attachedand the opposing face is face to face with and rotatable against theinside face of the front cover plate 347, which is attached to the bodyportion 341 and not rotatable.

As seen in FIGS. 79 and 81 in dotted outline and in perspective in FIG.72, the reverse side of the cover plate 347 is provided with threeequiangularly-spaced channels 355 which are open sided towards thedisc-like member 354 and extend radially outwardly from the centralaperture 347a of the cover plate. Inserted reciprocably in each radiallyextending channel 355 from the central aperture 347a is a leg portion356 of an "L"-shaped spreader finger element indicated generally by thereference numeral 339. The spreader finger portions 358 extend out ofthe central aperture 347a of the front cover plate 347 substantiallyparallel to the axis of the bore 344 to form a cluster and it is thiscluster that is manipulated radially apart to spread a tubular segment,such as a tubular segment end portion of a pinch valve element, topermit telescopic assembly thereof upon, i.e., concentrically with, alength of tubing. The spreader finger portions 358, upon which tubularsegments are placed for spreading, i.e., stretching to a largercross-sectional opening, during telescopic assembly of a flexibletubular segment with a length of tubing according to the invention, arepreferably quite thin for easier removal of the assembled tubularsegment and tubing combination from the assembly apparatus. In thisregard it should be noted that the spreader fingers 358 are sandwichedbetween a tubular segment end portion 82, 83 of the pinch valve elementand the tubing 49 when the spreader fingers are retracted prior to theejection step.

In FIGS. 68, 70 and 71, the disc-like member 354 is shown to have formedtherein three parallel and radially, i.e. spirally, outward extendingspiral guideways 360 which are open-sided towards the cover plate 347.Each spiral guideway extends spirally out in the same direction ofrotation from the central aperture 354a of the disc-like member 354.Each leg portion 356 of a respective "L"-shaped spreader finger element339 is provided with a guide pin 359 fixedly attached thereto thatextends laterally from the radial channel 355, of the cover plate 347,in which the leg portion 356 reciprocates, into one of the spiralguideways 360 along which it is slideable. Instead of the spiralguideways shown cut entirely through the disc-like member 354, theguideways 360 may be grooves cut to the same pattern if they are eachdeep enough to readily receive and slideably guide a guide pin 359during rotation of the disc-like member 354 and the grooves are opensided towards the cover plate 347.

Upon rotation of the disc-like member 354, using the knurled controlring 357 or the lever 361 to rotate the rotatable sleeve 149 to whichthe disc-like member 354 is attached, cam-like action is obtained toradially spread or retract the spreader finger portions 358 away from ortowards the common axis as the leg portions 356 are moved radially bythe respective guide pins 359 sliding in the spiral grooves 360. Ifdesired, the lever 361 may be attached to the control ring 357 as seenin FIG. 64 and used to rotate the control ring 357 through a sufficientarc to obtain the desired spreading and retracting of the spreaderfinger portions 358.

Positioned in the cylindrical passageway of the rotatable sleeve 149 andextending rearwardly therefrom is the reciprocable piston 362 thatreciprocates through a short range of movement within the cylindricalpassageway of the rotatable sleeve 149 to carry out the very importantejection procedure. The piston 362 is urged resiliently out of thepassageway of the rotatable sleeve 149 by a coil spring 363 that bearsat one end of the coil spring against the annular portion of the face ofthe disc-like member 354 that extends radially inward from the centralaperture of the rotatable sleeve 149, and at the other end, against thefirst end 365 of the piston 362. The rear portion 364 of the second endof the piston is of a slightly smaller diameter than the first portion365, the rear end of the larger diameter portion constituting a shoulderon the piston, and the second retainer ring 366 attached to the controlring 357 has a central aperture smaller enough than the larger diameterof the first end portion 365 of the piston to catch the shoulder andlimit the reciprocation of the piston 362 in the rearward direction.

Mounted in a recess 336 in the face of the first end 365 of the piston362 is an ejector block 368 that is dimensioned longitudinally to serveas a stop to accurately limit the depth of insertion of a length oftubing on which a tubular segment, such as a pinch valve element, is tobe emplaced.

In FIGS. 84 and 85 there is shown in section an assembly apparatus withan ejector block 368a with a longer axial dimension that provides ashallower stop for flexible tubing inserted into the apparatus for thepurpose of assembling the second tubular segment end portion of a pinchvalve element as a second step in the process of assembling a pinchvalve.

A central guide rod 369 extends axially from the ejector block 368 or368a through the passageway of the rotatable sleeve 149 andsubstantially to the outward ends of the spreader finger portions 358where it is centered between them. It serves as a guide over whichflexible tubing is inserted into the assembly apparatus. Also pivotablymounted are ejector arms 371 that extend forwardly along inside thepassageway of the rotatable sleeve 149 and nearly parallel to the commonaxis and out through the aperture 354a in the disc-like member 354 andaperture 347a in the cover plate 347 where they each rest against theradially outward surface of a spreader finger portion 358, beingcollectively resiliently urged against respective spreader fingerportions by a springy resilient annular member 372, such as an "O" ring.The ejector arms 371 must be selected to be of the appropriate length tocontact and bear against the edge of a flexible tubular segment, such asa tubular end portion of a pinch valve element, that has just beenemplaced on a length of flexible tubing extending into the apparatus,simultaneously with contact and pressure between the ejector block andthe inner end of the flexible tubing within the apparatus, in order toavoid moving or displacing the tubular end portion longitudinally of theflexible tubing during ejection. Because of the elastic radially inwardtension of the tubular end portions of the pinch valve element upon theflexible tubing, which has an outer diameter as great or greater thanthe inner diameter of the tubular segments, it is not practicallyfeasible to remove the assembled pinch valve from the spreader fingers,without risking altering of the positions of the tubular segment endportions of the pinch valve element, unless use is made of the ejectioncomponents of the apparatus.

The second part 364 of the reciprocable ejection piston 362 is shown inFIGS. 60 and 63 to be supported by a support element 374 having a lowersection 375 thereof attached to the rear of the base portion 342 of theassembly apparatus and an upright leg portion 376 extending upwardly tocontact the rear part 364 of the piston which is slideable on theflanged upper end 377 of the leg portion 376. A section 378 of theunderside of the rear part 364 of the piston 362 is ground flat fromadjacent the second end to the larger diameter forward part 365 of thepiston 362, and it is this flat section that rests upon the flangedupper end 377 of the leg portion 376 of the support element 374. Theflat nature of the underside section 378 serves to prevent the piston362 from rotating during use, and the shoulders 378a, 378b formed ateach end of the flat section 378 catch, respective, on the flanged upperend 377 of the support element 374 and on the second retainer ring 366to provide respective stop actions in the reciprocal motion of thepiston 362.

The base, body portion, and parts such as the cylindrical sleeve,reciprocable piston, control ring and both retainer rings, cover plateand disc-like member, of the assembly apparatus may be made of mildsteel or of an easily machinable metal, such as aluminum alloy, ifdesired, but are preferably made of tool steel or stainless steel.Preferably the spreader fingers and the ejector arms are made of toolsteel or stainless steel to provide greater strength and durability inthe thinner members.

In manufacturing a tension responsive pinch valve of the sort definedherein, it is essential to the proper valving action of the pinch valvethat the tubular segment end portions of the pinch valve element bepositioned with some accuracy spaced apart a rather short intervallongitudinally, i.e., linearly, of the length of tubing, with themagnitude of the interval or spacing being substantially greater thanthe length of the shank of the pinch valve element. Such larger spacinglinearly along the tubing is essential in order to obtain a doublingover of the tubing that produces a pinching shut of the embraced portionof the tubing when there is no tension on the portion of the length oftubing that includes the pinch valve per se and the shank of the pinchvalve element tends to elastically assume about its normal length,drawing the attached tubular segment end portions mutually closer.Proper spacing during telescopic assembly is readily achievable in aconvenient, efficient way using two nearly identical embodiments of theassembly apparatus described herein differing primarily in havingejector blocks of differing appropriate lengths to assemble therespective tubular segments. The ejector blocks serve as stops inindexing the length or extent of the end of the length of flexibletubing that can extend into the assembly apparatus during the assemblyprocess, thus controlling the positioning of the tubular segment endportions.

The first embodiment of the assembly apparatus utilized will have arelatively short ejector block, such as that identified by the referencenumeral 368 in FIGS. 63 and 67 and shown in perspective view in FIG. 65,so that the end of the length of tubing will extend relatively deep intothe assembly apparatus and the first tubular segment end portion of thepinch valve element will be emplaced far enough from the inserted end ofthe flexible tubing to leave room for the positioning of the secondtubular segment end portion. The telescopic assembly of the secondtubular segment end portion can only be performed closer to the insertedend of the length of tubing, using the assembly apparatus, than thelocation of the emplacement of the first tubular segment end portion.

The second embodiment of the assembly apparatus used to telescopicallyassemble the second tubular segment end portion must have a longerejector block such as that identified by the reference numeral 368a inFIGS. 84 and 85 and shown in perspective view in FIG. 66, so that theflexible tubing will be stopped at a shallower depth for the assembly ofthe second pinch valve tubular segment end portion closer to the end ofthe length of flexible tubing than the first tubular segment endportion. The ejector block 368a may be seen in FIG. 66 to have a smallerdiameter extension 338b that serves as the actual stop within theassembly apparatus for the end of the length of tubing inserted duringassembly operations. The extension 338b has a smaller diameter than theejector block 368a in order to leave circumferential annular spacewithin the rotatable sleeve 149 for the coil spring 363.

Referring now to FIG. 73 there is depicted an embodiment of the assemblyapparatus, along with a flexible pinch valve element 80 and a length 49of flexible tubing of the same diameter depicted in exploded view. Thepinch valve element 80, which consists of first 82 and second 83foreshortened tubular segments as end portions joined by a short shankportion 84 of about the same length as the end portions, is about to betelescopically assembled on the length 49 of flexible tubing near an endthereof. The embodiment of the assembly apparatus shown in FIG. 73 is tobe understood to be equipped with an ejector block 368 of appropriatelength for positioning the first tubular segment 82 of the pinch valveelement 80.

The pinch valve element 80 is seen in FIG. 74 to be poised for assemblyon the length 49 of flexible tubing with the shank portion 84 of thepinch valve element bent aside to hold the second tubular segment endportion 83 out of the way so the first tubular segment end portion 82can be slipped over the spreader finger portions 358 that are retractedclose together as a cluster as depicted in FIG. 74. In FIG. 75 thetubular segment end portion 82 is shown slipped onto the cluster ofspreader finger portions 358. The inner edge of the first tubularsegment end portion should be in contact with the ends 37a of theejector arms 31 to ensure accurate positioning during the assemblyprocess. The section view in FIG. 76 also shows the tubular segment endportion 82 slipped onto the spreader finger portions 358. In FIG. 76 itis also seen that the apparatus is equipped with a fairly short ejectorblock 368 inside the first end 365 of the ejector piston 362.

Rotation of the control ring 357, which concentrically surrounds and isattached to the rear end of the larger diameter portion of the rotatablesleeve 149, causes rotation of the rotatable sleeve as well as thedisc-like member 354 which is mounted on the front end 350 of therotatable sleeve. Rotation of the disc-like member 354 forces the guidepins 359 attached to respective leg portions 356 of spreader fingerelements 339 to slide along the spiral guideways of the disc-likemember, giving cam-like action moving the leg portions 356 in a radialdirection within the radial channels in the cover plate 347 and thespreader finger portions 358 of the spreader finger elements 339 areconsequently moved radially as well, which is the desired action. Thedirection and extent of rotation of the disc-like member 354 determinesthe radial direction and extent of movement of the spreader fingerportions 358.

In the next assembly step the control ring 357 is then grasped androtated manually, or the lever 361 may be used to rotate the controlring 357, in the appropriate direction and through an arc sufficient tospread the spreader finger portions 358, thus stretching the firsttubular segment end portion 82 open as shown in FIGS. 77, 78 and 79.Turning the control ring 357 sufficiently stretches the tubular segment82 enough to admit the end of the length of tubing 49 which is then slidthrough the tubular segment with little or no friction and onto centralguide rod 369 until the end of the length of tubing hits the ejectorblock 368, which serves as a stop for the proper positioning of thetubular segment end portion 82 on the length of tubing 49.

The control ring 357 is then rotated as by moving the lever 361 backtowards its starting position to relax the spreading tension on thefirst tubular segment end portion 82, completing the assembly step forthe first tubular segment end portion.

To carry out ejection, the ejector piston 362 is moved forward (towardsthe first surface 345 of the body portion 341) by any suitable meansagainst the coil spring 363 to move the ejector piston a small distanceor spacing from a position with the second or rear end 364 extendingback beyond the support element 374 until the ejector piston 362 reachesa pre-set stop as seen in FIG. 80 where the rear edge 378a of theflattened lower surface 378 of the rear part 364 of the piston is caughtby the upstanding flanged upper end 377 of the upright leg section 376of support element 374. The piston 362 carries forward the ejector block368 and the ejector arms 371 which contact and eject simultaneously andrespectively the end of the length of tubing 49, and the nearest edge ofthe emplaced tubular segment 82 which is contacted by the ends of theejector arms 371a, as can be seen in FIGS. 80 and 81. At the pre-setstop the ejector arms 371 and the ejector block 368 will havecoordinately mechanically ejected with simultaneous pressure the length49 of flexible tubing and the emplaced first tubular end portion 82 ofthe pinch valve element.

While the piston 362 is readily slid forward manually towards the coverplate 347 if the coil spring 363 is selected to be of a suitable springtension, the piston 362 may be equipped to be reciprocated hydraulicallyor electromagnetically, if desired.

In FIG. 82 the partly assembled pinch valve depicted in FIG. 80 is shownpoised to be further assembled using a second embodiment of the assemblyapparatus with a different, i.e., shallower depth stop, in the form of alonger ejector block 368a with an extension 338b. The short end section85 of the length 49 of flexible tubing between the leading end thereofand the emplaced first tubular segment end portion 82 of the pinch valveelement 80 has been bent out of the way so as not to impede sliding thesecond tubular segment end portion 83 onto the retracted spreader fingerportions 358 of the assembly apparatus until the tubular segment endportion contacts the ends of the ejector arms 371a, the shank portion 84of the pinch valve element 80 being much shorter than the section oftubing 85a disposed between assembled, i.e., emplaced, tubular segmentend portions 82 and 83.

The second tubular segment end portion 83 of the pinch valve element isthen slid onto the spreader finger portions 358 and the control ring 357is rotated to spread the spreader finger portions 358 and stretch thesecond tubular segment end portion 83 of the pinch valve element 80,similar to what is seen in FIG. 77, and the short end section 85 of thelength 49 of flexible tubing is bent over sharply and the leading end isslipped inside the spreader finger portions 358 and the stretched secondtubular segment end portion 83 and over the central guide rod 369 and upagainst the ejector block 368a as shown in FIGS. 83 and 84.

As indicated, the longer ejector block 368a, having an extension 338b,provides a stop at a shallower depth of penetration by the end 85 of thelength of tubing 49 inside the apparatus. The ejector block 368a isselected to have an extension 338b of appropriate length to provideindexing at a selected depth of penetration desired for the end 85 ofthe length of tubing 49 in order to achieve proper placement of thesecond tubular segment end portion 83.

To complete the assembly of the second tubular segment end portion 83 ofthe pinch valve element, the control ring 357 is rotated back to retractthe spreader finger portions 358 closer together to relieve the tensionon the second tubular segment end portion 83. To carry out ejectionsubstantially in the same manner as described for the first emplacedtubular segment end portion 82, the ejection piston 362 is pressedforward against the action of the coil spring 363 until the rear edge378a of the flat lower surface 378 of the rear portion 364 of theejection piston 362 is stopped by the flanged upper end 377 of theupright leg portion 376 of support element 374, whereupon the length 49of flexible tubing and the second tubular segment end portion 83 of thepinch valve element emplaced thereon will be found to have been ejectedas a unit and the manufacture of the flexible pinch valve is completed.

It is preferred to complete the manufacture of the pinch valve byinserting a small amount of an adhesive such as a room temperaturevulcanizing silicone adhesive along the margins of the tubular segmentend portions of the valve element.

We claim:
 1. A fluid delivery set comprising:a fluid communication meanshaving a first end which is connectable to or integral with a supplycontainer and a second end which is connectable to or integral with ameans for introducing an enteral or parenteral fluid into the body of apatient; the fluid communication means comprising a drip chamber with aretention element attached thereto and a retention/connector device,and, at least first, second and third lengths of flexible tubing, thefirst length of flexible tubing being connected to the drip chamber andbeing connectable to or integral with a supply container, the secondlength of flexible tubing connecting the drip chamber and theretention/connector device, and the third length of flexible tubingbeing connected to the retention/connector device and being connectableto or integral with a device for administering a fluid within the bodyof a patient; and the fluid communication means at about theretention/connector device being shaped into a bend with a radius of nomore than 0.5 inch and at an angle in the range of about 78 to about 102degrees.
 2. The fluid delivery set of claim 1 wherein the radius of thebend does not exceed about 0.375 inch.
 3. The fluid delivery set ofclaim 1 wherein the angle of the bend is in the range of about 85 toabout 95 degrees.
 4. The fluid delivery set of claim 1 wherein the bendin the communication means is within the retention/connector element. 5.The fluid delivery of claim 1 wherein the retention/connector element isprovided with a tab for grasping.
 6. The fluid delivery of claim 1wherein the retention/connector device has a retention tab extendinglaterally thereof that is adapted to interlock with a receptacle of apump housing.
 7. The fluid delivery set of claim 1 wherein the retentionelement that is attached to the drip chamber is attached around theupper part of the drip chamber has a lower surface that is adapted tomate with a retentive receptacle of a pump housing.
 8. The fluiddelivery of claim 1 further comprising a tension responsive pinch valveoperatively associated with a flexible tubing portion.
 9. A fluiddelivery set for enteral or parenteral fluids comprising:a drip chamberhaving an inlet and an outlet, a retention/connector device, and atleast first, second and third lengths of flexible tubing each havingfirst and second ends; the inlet of the drip chamber being connected tothe first end of the first length of flexible tubing and the second endof first length of flexible tubing being connectable to or integral witha supply container; the outlet of the drip chamber being connected to afirst end of the second length of flexible tubing, a second end of thesecond length of flexible tubing being connected to theretention/connector device, a first end of the third length of flexibletubing being connected to the retention/connector device, and a secondend of the third length of flexible tubing being connectable to orintegral with a device for administering a fluid within the body of apatient the drip chamber having a first retention element associatedwith the upper part thereof, the first retention element being adaptedto fit into a first retentive and supportive receptacle of a housing ofa rotary peristaltic pump therefor; the retention/connector device beinghollow tubular in form having a fluid passageway formed therethrough andformed of the juncture of two tubular leg portions to which the secondand third lengths of flexible tubing are connected, respectively, theretention/connector device being adapted to fit into a second retentivereceptacle of the housing of a rotary peristaltic pump; the leg portionsof the retention/connector device being joined at about a right anglebend wherein the cross section of the lumen of the retention/connectordevice is not substantially reduced when the bend radius is not greaterthan about 0.5 inch.
 10. The fluid delivery set of claim 9 wherein theretention/connector device has a retention tab extending laterallytherefrom at about the bend, the retention tab being adapted to nest inthe second retentive receptacle.
 11. The fluid delivery set of claim 9wherein the second length of flexible tubing extending between the dripchamber and the retention/connector device is of the requisite lengthfor the second length of flexible tubing to be under operative occlusivepressure against the rollers of a peristaltic rotor of a complementaryperistaltic pump when the fluid delivery set is operatively assembledwith said peristaltic pump with the second length of flexible tubingextending from the outlet of the drip chamber around and against theperistaltic rotor to the retention/connector device in the secondretentive receptacle.
 12. The fluid delivery set of claim 9 wherein thetwo leg portions of the retention/connector device meet and form about aright angle bend and the retention tab extends laterally from about thebend at an angle of about 180 degrees from the leg portion to which thefirst end of the third length of flexible tubing is connected.
 13. Thefluid delivery of claim 9 further comprising a tension responsive pinchvalve operatively associated with the second length of flexible tubing.